Google Colab NameError: name 'os' is not defined

[iansquenet]

05. Privileged Rappers.flac(audio/x-flac) - 30820146 bytes, last modified: n/a - 100% done

Saving 05. Privileged Rappers.flac to 05. Privileged Rappers (1).flac

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NameError                                 Traceback (most recent call last)

[<ipython-input-4-58465cc5fe2d>](https://localhost:8080/#) in <module>
     14   res=files.upload()
     15   filename=list(res.keys())[0]
---> 16   os.rename(filename,"songs/"+filename)

NameError: name 'os' is not defined